GPT-5 Pro vs xAI: Grok 4.5
Compare GPT-5 Pro by OpenAI against xAI: Grok 4.5 by xAI, context windows of 400K vs 500K, tested across 41 shared challenges.
Our Verdict
GPT-5 Pro
xAI: Grok 4.5
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
xAI: Grok 4.5 is 20x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
GPT-5 Pro
Input
$15.00
Output
$120.00
xAI: Grok 4.5
Input
$2.00
7.5× cheaper
Output
$6.00
20× cheaper
xAI: Grok 4.5 is cheaper on both — 7.5× input, 20× output
Writing DNA
Style Comparison
Similarity
76%
xAI: Grok 4.5 uses 245.4x more bold
GPT-5 Pro
xAI: Grok 4.5
65%Vocabulary61%
15wSentence Length16w
0.32Hedging0.23
0.0Bold2.5
2.9Lists2.4
0.00Emoji0.09
0.00Headings0.48
0.01Transitions0.06
Based on 11 + 27 text responses
Research
What we learned reading every model
FAQ
